Not Applicable
1. Field of the Invention
The present invention relates to a golf club head with an internal hosel and a method of manufacturing the same. More specifically, the present invention relates to a golf club head with an internal hosel moved inward off of the striking plate and a method of manufacturing the same.
2. Description of the Related Art
When a golf club head strikes a golf ball, large impacts are produced that load the club head face and the golf ball. Most of the energy is transferred from the head to the golf ball, however, some energy is lost as a result of the collision. The golf ball is typically composed of polymer cover materials (such as ionomers) surrounding a rubber-like core. These softer polymer materials having damping (loss) properties that are strain and strain rate dependent which are on the order of 10-100 times larger than the damping properties of a metallic club face. Thus, during impact most of the energy is lost as a result of the high stresses and deformations of the golf ball (0.001 to 0.20 inches), as opposed to the small deformations of the metallic club face (0.025 to 0.050 inches). A more efficient energy transfer from the club head to the golf ball could lead to greater flight distances of the golf ball.
The generally accepted approach has been to increase the stiffness of the club head face to reduce metal or club head deformations. However, this leads to greater deformations in the golf ball, and thus increases in the energy transfer problem.
Some have recognized the problem and disclosed possible solutions. An example is Campau, U.S. Pat. No. 4,398,965, for a Method Of Making Iron Golf Clubs With Flexible Impact Surface, which discloses a club having a flexible and resilient face plate with a slot to allow for the flexing of the face plate. The face plate of Campau is composed of a ferrous material, such as stainless steel, and has a thickness in the range of 0.1 inches to 0.125 inches.
Another example is Eggiman, U.S. Pat. No. 5,863,261, for a Golf Club Head With Elastically Deforming Face And Back Plates, which discloses the use of a plurality of plates that act in concert to create a spring-like effect on a golf ball during impact. A fluid is disposed between at least two of the plates to act as a viscous coupler.
Yet another example is Jepson et al, U.S. Pat. No. 3,937,474, for a golf Club With A Polyurethane Insert. Jepson discloses that the polyurethane insert has a hardness between 40 and 75 shore D.
Still another example is Inamori, U.S. Pat. No. 3,975,023, for a Golf Club Head With Ceramic Face Plate, which discloses using a face plate composed of a ceramic material having a high energy transfer coefficient, although ceramics are usually harder materials. Chen et al., U.S Pat. No. 5,743,813 for a Golf Club Head, discloses using multiple layers in the face to absorb the shock of the golf ball. One of the materials is a non-metal material.
Lu, U.S. Pat. No. 5,499,814, for a Hollow Club Head With Deflecting Insert Face Plate, discloses a reinforcing element composed of a plastic or aluminum alloy that allows for minor deflecting of the face plate which has a thickness ranging from 0.01 to 0.30 inches for a variety of materials including stainless steel, titanium, KEVLAR(copyright), and the like. Yet another Campau invention, U.S. Pat. No. 3,989,248, for a Golf Club Having Insert Capable Of Elastic Flexing, discloses a wood club composed of wood with a metal insert.
Although not intended for flexing of the face plate, Viste, U.S. Pat. No. 5,282,624 discloses a golf club head having a face plate composed of a forged stainless steel material and having a thickness of 3 mm. Anderson, U.S. Pat. No. 5,344,140, for a Golf Club Head And Method Of Forming Same, also discloses use of a forged material for the face plate. The face plate of Anderson may be composed of several forged materials including steel, copper and titanium. The forged plate has a uniform thickness of between 0.090 and 0.130 inches.
Another invention directed toward forged materials in a club head is Su et al., U.S. Pat. No. 5,776,011 for a Golf Club Head. Su discloses a club head composed of three pieces with each piece composed of a forged material. The main objective of Su is to produce a club head with greater loft angle accuracy and reduce structural weaknesses. Finally, Aizawa, U.S. Pat. No. 5,346,216 for a Golf Club Head, discloses a face plate having a curved ball hitting surface.
The Rules of Golf, established and interpreted by the United States Golf Association (xe2x80x9cUS GAxe2x80x9d) and The Royal and Ancient Golf Club of Saint Andrews, set forth certain requirements for a golf club head. The requirements for a golf club head are found in Rule 4 and Appendix II. A complete description of the Rules of Golf is available on the USGA web page at www.usga.org. Although the Rules of Golf do not expressly state specific parameters for a golf club face, Rule 4-1e prohibits the face from having the effect at impact of a spring with a golf ball. In 1998, the USGA adopted a test procedure pursuant to Rule 4-1e that measures club face COR. This USGA test procedure, as well as procedures like it, may be used to measure club face COR.
Although the prior art has disclosed many variations of face plates, the prior art has failed to provide a face plate with a high coefficient of restitution composed of a thin material, and to construct a golf club that allows for maximum performance from the face plate.
The present invention provides a golf club head with an interior hosel that is disposed inward from a striking plate allowing for greater compliance of the striking plate with a golf ball during impact. A more compliant striking plate provides for lower energy loss and a higher coefficient of restitution.
One aspect of the present invention is a method for producing a golf club head with an internal hosel. The method includes providing a face member that has a striking plate with an interior surface and a face extension extending laterally inward from the interior surface of the striking plate. The face extension has an upper portion, a lower portion and a heel wall. The method also includes drilling a hole through the upper portion of the face extension in proximity to the heel wall. The method also includes placing a cylinder in alignment with the hole in the upper portion. The method further includes attaching the cylinder to the upper portion and the lower portion of the face extension with the cylinder disposed inward from the striking plate.
Another aspect of the present invention is a golf club head including a face member, an interior hosel, a crown and a sole. The face member includes a striking plate for striking a golf ball. The striking plate has an exterior surface, an interior surface, and a perimeter. The striking plate extends from a heel section of the golf club head to a toe section of the golf club head. The face member also includes a face extension extending laterally inward along the entire perimeter of the striking plate. The face extension has an upper portion, a lower portion opposite the upper portion, a heel wall in the heel section of the golf club head and substantially perpendicular to the face plate, and a toe wall in the toe section of the golf club head. The interior hosel receives a shaft and is attached to the upper portion of the face extension and the lower portion of the face extension. The entire interior hosel is disposed inward from the striking plate thereby allowing for compliance of the striking plate during impact with a golf ball. The crown member is secured to the upper portion of the face extension at a predetermined distance from the striking plate. The sole member is secured to the lower portion of the face extension at a predetermined distance from the striking plate.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.